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Still idles like shit. I posted a video on facebook of it a little while ago:https://www.facebook.com/josh.sincla...2868632735354/
No codes related to how it would run (ie MAP, TPS, O2, etc.)
Also likes to really bog, stumble and backfire under load at low RPM under WOT (stop to 25 MPH).

So yesterday I did the following things to try and sort it out:
Changed the plugs for new Autolite Copper plugs
Changed the TFI module
Changed the ignition coil
Changed the MAP sensor (with a used one I had laying about)
Checked TPS voltage. About .9v at idle position, just over 4v at WOT. New TPS and MAP ordered just for the hell of it.
Switched O2 sensor connectors from side to side
Filled up with premium gas (gas that was in the car was what sat in the tank all winter)

Result was a *slightly* smoother idle, but now it runs like absolute garbage under part throttle while driving it. Feels like the plug wires have been switched around and it's wired wrong. Constantly bucking, misfiring and backfiring. It's been hard on gas since the HO conversion, which is also when it started running bad. Old engine was an environmental disaster with the oil leaks, it rattled and clattered while cold but ran silky smooth and still pulled hard on the bottom end, and was good on gas. New setup is the opposite; it idles without knocking, pulls hard at speed, bogs and runs like shit at idle and down low, burns gas like a champ, and does not use any oil.
During the process of switching the O2 connectors, I broke the orange ground wire off the back of the intake manifold. But, the driveability problems I described were like it both before and after the ground wire got broken.

93 truck engine block with E7 heads
Original upper intake manifold, EGR spacer bored out to 58mm to match the 86 Mustang TB that has been reversed for LH intake panther setup.
IAC is new within last 5 years, cleaned annually (it's never dirty when removed, entire intake system is clean since I fixed the coolant leak)
New 19 lb fuel injectors. Fuel pressure and flow OK
New 155 lph BBK fuel pump
86 Mustang 5.0 HO camshaft
All new engine internals. Valvetrain new except for valves and valve springs
ECM is a Lincoln Mark VII part, unsure of exact year or three-digit ID code. Cruise control still works
EGR and all related components deleted. No EGR codes from reader
Cats cleaned out, smog pump and all related components are removed
Lincoln Logs for headers
NTK O2 sensors <2 years old
New VSS

Any ideas? I'm starting to lose my patience with this...."do an HO conversion" they said, "it will be fun" they said...nothing but headaches since I did it. Can't get it to run right now for about two years.

I understand the HO is going to be a dog on the bottom end off the line, especially with my 3.08 gears due to the cam's higher revving tendencies than the original lopo unit. But that shouldn't include backfiring and abysmal fuel economy, rough idling, stalling, etc.

Thanks in advance

So I had a long night in the garage tonight.

Pulled the O2 sensor wiring harness up from below, which was easy give the orange ground wire was broken off from yesterday's misadventures.

I cut the heat resistant sleeves off the harness to find one of the wires was broken inside of it. I had tried switching the O2 plugins from side to side already, no difference was made to the way it ran. Broken wire on the other hand...

So I fixed that wire, put the heat resistant sleeve back on the loom and double checked the EVTM to make sure I had the correct side plugged in to the O2 sensor. Reattached the orange ground wire and put that to bed. Good job.

Started it up, took it for a drive to bring it to operating temperature and set the IAC/TPS. surging idle seemed slightly better but did it ever misfire and backfire badly.

Took out each plug one by one and found the #3 plug's electrode was smashed into the plug itself. The I remembered that I dropped it when I was changing the plugs over the weekend. Pried it apart and set the gap. Double checked the tightness of the plug wires and took it for a spin.

OMG! It ran the best it ever did since I did the HO conversion! Pulled hard and ran smooth as could be!

Stopped at the grocery store on the way home, picked up a couple things. Got home and proceeded to change the oil after sitting all winter and driving the shit out of it for the past few days....

After the oil was changed, I turned the key and got a definitive "I'm not going to start for you now" click. Click, Click click click. Not a gig.

Three solenoids, two hours and one very upset hombre later, I found the problem. The starter cable terminal was loose on the starter. No big deal, just tighten it up, right?

Wrong.

It just spun around in circles. Stripped like the girls at The Brass Rail.

I then found a small nut and bolt combo that almost worked to tighten up the loose cable. I'm not happy with how not completely snug it is, but at least it started for me again.

Wouldn't care so much except I only just took it out of winter storage not so long ago and I have to go on a 3800 km (2400 mile) trip in it this coming weekend.